The place has a very nice atmosphere--distressed wide-planked pine flooring, red brick, dim lighting, picture windows over looking the old harbor. You're not going to do much better in Reykjavik (unless you go to the Pearl with its revolving restaurant that lets you see the whole city)
I got the fish of the day lunch special, which was catfish (this is not the same as American Catfish--this is Atlantic Catfish, aka Wolffish, Scotch Halibut). It was prepared perfectly with some kind of fruity sauce on it and served with potatoes, a small salad and fresh sourdough bread. I had a beer with it and the total was about $30 US.
Though the restaurant wasn't full, there were many other groups/couples (alas, I was the only single) and the service was great.
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